On 2/13/13 2:12 PM, Eric Sandeen wrote:
> On 2/13/13 1:50 PM, Eric Sandeen wrote:
>> On 2/13/13 12:09 PM, Rémi Cailletaud wrote:
>>> Le 13/02/2013 18:52, Eric Sandeen a écrit :
>>>> Did the filesystem grow actually work?
>>>> # xfs_db -c "sb 0" -c "p" /dev/vg0/tomo-201111
>>>> magicnum = 0x58465342
>>>> blocksize = 4096
>>>> dblocks = 10468982745
>>>> That looks like it's (still?) a 38TiB/42TB filesystem, with:
>>>> sectsize = 512
>>>> 512 sectors.
>>>> How big was it before you tried to grow it, and how much did you try to
>>>> grow it by? Maybe the size never changed.
>>> Was 39, growing to 44. Testdisk says 48 TB / 44 TiB... There is some chance
>>> that it was never really growed.
>>>> At mount time it tries to set the sector size of the device; its' a
>>>> hard-4k device, so setting it to 512 fails.
>>>> This may be as much of an LVM issue as anything; how do you get the LVM
>>>> device back to something with 512-byte logical sectors? I have no idea...
>>>> *if* the fs didn't actually grow, and if the new 4k-sector space is not
>>>> used by the filesystem, and if you can somehow remove that new space from
>>>> the device and set the LV back to 512 sectors, you might be in good shape.
>>> I dont either know how to see nor set LV sector size. It's 100% sure that
>>> anything was copied on 4k sector size, and pretty sure that the fs did not
>>> really grow.
>> I think the same blockdev command will tell you.
>>>> Proceed with extreme caution here, I wouldn't start just trying random
>>>> things unless you have some other way to get your data back (backups?).
>>>> I'd check with LVM folks as well, and maybe see if dchinner or the sgi
>>>> folks have other suggestions.
>>> Sigh... No backup (44To is too large for us...) ! I'm running a testdisk
>>> recover, but I'm not very confident about success...
>>> Thanks to deeper investigate this...
>>>> First let's find out if the filesystem actually thinks it's living on the
>>>> new space.
>>> What is the way to make it talk about that ?
>> well, you have 10468982745 4k blocks in your filesystem, so 42880953323520
>> bytes of xfs filesystem.
>> Look at your lvm layout, does that extend into the new disk space or is it
>> confined to the original disk space?
> lvm folks I talk to say that if you remove the 4k device from the lvm volume
> it should switch back to 512 sectors.
> so if you can can convince yourself that 42880953323520 bytes does not cross
> into the newly added disk space, just remove it again, and everything should
> be happy.
> Unless your rash decision to start running "testdisk" made things worse ;)
I tested this. I had a PV on a normal 512 device, then used scsi_debug to
create a 4k device.
I created an LV on the 512 device & mounted it, then added the 4k device as you
did. growfs failed immediately, and the device won't remount due to the sector
I verified that removing the 4k device from the LV changes the LV back to a 512
However, I'm not 100% sure how to remove just the 4K PV; when I did it, I did
something wrong and it reduced the size of my LV to the point where it
corrupted the filesystem. :) Perhaps you are a better lvm admin than I am.
But in any case - if you know how to safely remove ONLY the 4k device from the
LV, you should be in good shape again.